Expansible and contractible mold core



March 30, 1937. T. SCHUSTER EXPANSIBLE AND CONTRACTIBLE MOLD CORE FiledAug. 19, 1936 2 Sheets-Sheet l Elma/rm March 30, 1937. T. SCHUSTEREXPANSIBLE AND CONTRACTIBLE MOLD CORE Filed Aug. 19, 1956 2 Sheets-Sheet2 I 0 w w v 7 w Wm w w THOMAS SCI/U6 715/;

Patented Mar. 30, 1937 UNITED STATES PATENT OFFICE Thomas Schuster,Phoenix, Ariz. Application August 19, 1936, Serial No. 96,876

7 Claims.

This application relates to a new and improved core for concrete molds,said core being similar to the core disclosed in my U. S. Patent No.2,032,637, but not claimed therein, due to a requirement for 5 divisionbetween mold claims and core claims. It is the object of the inventionto provide a rather simple and inexpensive core provided with novelmeans for expanding it into operative relation with a surrounding moldwall, and for contracting it for removal from the molded article. Whilethe core is intended primarily for use in the molding of concrete boxesfor housing underground meters, and is therefore usually of rectangularform, it is to be understood that the invention is not restricted to anyparticular field of use nor to only one shape. It may be constructed invarious shapes on the contrary and used for the formation of numerouskinds of articles.

Figure 1 of the accompanying drawings is a top plan view of arectangular core constructed in accordance with the invention.

Fig. 2 is a central vertical longitudinal sectional view on line 2-2 ofFig. 1.

Fig. 3 is a fragmentary end elevation.

Fig. 4 is a vertical transverse sectional view on line 4-4 of Fig. 1.

Fig. 5 is a detail perspective view.

Fig. 6 is a top plan view showing a core of cylinfl drical form.

Fig. 7 is a fragmentary perspective view more clearly illustrating theparts shown in Fig. 3.

The rectangular core illustrated in Figs. 1 to 5 includes two verticalside walls 68 and four end 1 wall sections 69, there being one of theseend wall sections integrally joined to each end of each side wall 68.The inner edges of the end wall sections 69 are provided with integralvertical flanges 10 which project to the interior of the core, 40 saidflanges diverging toward the center of said core as shown. Two upper andtwo lower longitudinal springs 1| and 12 respectively extendhorizontally between the end wall sections 69 and are secured bysuitable fasteners 13 to the remote 45 sides of the flanges 10. Thecentral portions of these springs are secured to transverse plates orother tie members 14. The springs are preferably of the type commonlyused on vehicles and they are employed to contract the core. When 50 thecore is in contracted position, the springs are bowed away from eachother to a greater extent than when the two halves of the core arespread apart to their operative positions. In moving from normal bowedform to less bowed form, the 55 straight distances between the ends ofboth I springs 1| and 12 to contract the core.

springs, lengthen, causing said springs to exert an outward pressureupon the end wall sections 69, springing these end wall sectionsoutwardly to some extent. After molding of the article, when the springs1| and 12 are permitted to return to 5 normal and contract the core forremoval, said springs in moving back to their normal bowed positions,inwardly spring the end wall sections 69 to a slight extent from theaforesaid article,

facilitating removal of the core without injuring 10 said article.

For spreading the two halves of the core to operative position, Iprovide wedges 15 between the adjacent flanges 10, and operating meansfor said wedges, said operating means being mounted 15 upon the tiemembers 14. In the present showing, a vertical manually rotatable screw16 is rotatable in bearing openings in the tie members collar 80 withthe lower ends of said wedges.

The links may be of extensible and retractable 25 nature if desired,turnbuckles 83 being shown for varying their lengths. When the screw 16is turned in one direction, the nuts or collars 19 and 80 are movedtoward each other, thereby inwardly sliding the wedges 15 and allowingthe When screw 16 is tlurned in the other direction, the

' collars or nuts 19 and 80 are moved away from each other, causing thelinks 8| and 82 to outwardly force the wedges 15, expanding the core toits operative position. The outward movement of the wedges 15 is limitedby lateral lugs 84 on the ends of said wedges, which lugs strike theedges 85 of notches 8B in the inner edges of the flanges 10. Duringadjustment of the wedges 40 15, the lugs 84 move in and are guided bythe notches 86. By having the lugs 84 abut the edges 85, outwardpressure on the end wall sections 69, in addition to the pressureexerted by the springs 1| and 12, is provided.

In Fig. 6, the side Walls 68 and end wall sections 69 so merge into eachother as to jointly form a circular core designed primarily for moldingconcrete pipes, cylindrical meter box walls, or the like. Springs 1| ofslightly different form from the springs above described, are connectedwith the flanges 10' and are secured at their intermediate portions totie members 14' upon which the screw 16 is mounted 55 in use, the lugs81 rest upon a suitable pallet (not shown) upon which the mold wall andcore are also supported. This pallet may be of the general form shown inthe aforesaid Patent No. 2,032,637.

It will be seen from the foregoing that novel I and advantageousprovision has been made for carrying out the objects of the invention,and while the details disclosed may be considered as preferred,variations as to size, shape, proportions, and structural details, maybe made within the scope of the invention as claimed.

I claim:--

1. A core comprising side walls and end wall sections joined thereto,vertical wedges between said end wall sections for expanding said core,two upper and two lower longitudinal springs connected at their endswith said end wall sections for contracting the mold, an upper and alower transverse tie member extending between said upper springs andsaid lower springs respectively and secured to the central portionsthereof, and means mounted on saidtie members and connected with saidwedges for operating the latter.

2. A core comprising side walls and end wall sections joined thereto,the inner ends of said .end wall sections being provided with divergingvertical flanges projecting from the inner sides of said sections,twoupper and two lower longitudinal springs secured at their ends tosaid flanges for contracting the core, an upper and a lower transversetie member extending between said upper and said lower springsrespectively and secured to the intermediate portions thereof, verticalwedges between the aforesaid flanges for expanding the core, and meansmounted on said tie members and connected with said wedges for operatingthe latter.

3. A core comprising two side walls, end wall sections connected withthe ends of said side walls, laterally spaced longitudinal springsconnected at their ends with said end wall sections for contracting thecore, means connecting the central portions of said springs with eachother, and means for forcing said end wall sections away from each otherin directions transverse to the side walls, said springs being bowedaway from each other to cause said springs to outwardly force said endwall sections in directions parallel with said side walls when said endwall sections are forced in the first mentioned directions.

4. A core comprising side walls and end wall sections yieldably joinedthereto, the inner ends of said end wall sections being provided withdiverging flanges projecting inwardly from the inner sides of saidsections, wedges between said flanges, means for forcing said wedgesaway from each other to cause them to wedge said flanges apart andexpand the core laterally, and

means on said wedges to abut the inner edges of said flanges and forceoutwardly thereon to expand the core longitudinally.

5. A core comprising side walls and end wall sections yieldably joinedthereto, the inner ends of said end wall sections being provided withdiverging flanges projecting inwardly from the inner sides of saidsections, wedges between said flanges, means for forcing said wedgesaway from each other to cause them to wedge said flanges apart andexpand the core laterally, and lateral lugs on said wedges to abut saidflanges and force outwardly thereon to expand the core longitudinally,said flanges having notches receiving said lugs to guide the wedgesduring adjustment.

6. An expansible core having two wall sections in substantiallyedge-to-edge relation, means for expanding the core and separating saidwall sections, laterally projecting lugs on the adjacent edges of saidwall sections, and an arched strip straddling said lugs to form anopening through the material to be molded around the core.

'7. A core having wall sections, leaf or similar springs connected withsaid wall sections and holding them yieldably in predetermined relation,said springs extending across the interior of the core, tie members towhich the central portions of said springs are secured, wedges bea tweensaid wall sections for spreading the same,

and means mounted on said tie members for actuatingsaid Wedges.

THOMAS SCHUSTER.

